test=int(raw_input())
ir,ic,fr,fc=map(int,raw_input().split())
inter=abs(ir-fr)
lif=[]
cot=0
temp=0
if inter%2==0:
    difc=abs(ic-fc)
    if abs(difc-inter/2)%2==0:
        curow=ir
        cucol=ic
        while cucol!=fc or curow!=fr:
            temp=-1

            if fr<curow and fc<=ic:
                curow=curow-2
                cucol=cucol-1
                lif.append("UL")
                cot=cot+1

            if fr<curow and fc>cucol:
                curow=curow-2
                cucol=cucol+1
                lif.append("UR")
                cot=cot+1
            if fr>curow and fc>=cucol:
                curow=curow+2
                cucol=cucol+1
                lif.append("LR")
                cot=cot+1
            if fr>curow and fc<cucol:
                curow=curow+2
                cucol=cucol-1
                lif.append("LL")
                cot=cot+1
            if curow==fr:

                if fc<cucol:
                    cot=cot+abs(cucol-fc)/2

                    for i in xrange(abs(cucol-fc)/2):
                        lif.append("L")
                if fc>cucol:
                    cot=cot+abs(cucol-fc)/2
                    for i in xrange(abs(cucol-fc)/2):
                        lif.append("R")
                cucol=fc

if temp==-1:
    print cot
    print " ".join(lif)

else:
    print "Impossible"